On the one hand, prestige is a brilliant mechanic. It operates both as a scarce resource, and as a measure of victory at the end of a campaign. It's clean, simple, and can be easily tweaked to make things easier or harder. It functions to encourage caution by players, to limit force composition, and to punish reckless decisions.

On the other hand, the mechanic as currently designed has some quirks and limitations.

For one, many campaigns have a bit of a trajectory where you are meant to accumulate prestige in the early campaign, and spend it down in the late campaign. This varies a bit, but is especially true of the German Grand Campaign. The problem with that is that you may be falling behind the curve without really knowing it until it's far too late. If you run out of prestige in early '45, there's nothing you can do about it, because its the accumulated result of bad play from the very beginning. Or even bad play in 1939 and 1940, even if you played really well since then! So there is a huge lag between a mistake and the consequence for it. It can be very frustrating to find out that you don't have enough prestige to continue a campaign, after putting dozens or scores of hours into it. (Afrika Korps is better designed, with prestige feeling scarce throughout, but still always seems to be just enough around to scrape by...)

Second problem: prestige, like money, is a snowball. If you have lots of it, it's easy to get more. If you don't have much, it's hard to get more. Excess prestige can be used to upgrade units, and esp. to overstrength units, which though expensive can be a very good investment, because the overstrengthed units more than pay themselves off in avoided casualties. (Esp. overstrength artillery). Conversely, if you're out of prestige, it's harder to do these things which allow prestige savings over the long term. Complicating matters is the fact that campaigns are generally designed to keep up with a very good player, because otherwise good players would outstrip the campaign, run ahead of the power curve and get bored.

Third problem: Having a big bucket of prestige can take the tension and sense of scarcity out of individual battles. The battles can become a bit bland if what you're tracking is your overall prestige pool trajectory, rather than the particular constraints of the individual battle. If you can always fully replace a unit (provided you have enough prestige), an important tool is taken out of the hands of scenario designers, who otherwise could play with different levels of replacement availability to control the pace and feel of a battle.

So here's a proposal... create two separate resources.

"Prestige" would still be there, as an abstract representation of your reputation and success, and consequently your influence over resource allocation. Prestige would be calculated after each battle, and would be based on your level of victory, speed of victory (bonus points for winning with turns to spare!), taking bonus objectives, and your casualties inflicted and sustained. You should lose prestige for all casualties, including auxiliary units, thus removing the incentive to use them as mere fodder.

Prestige would be used for unit upgrades, special perks like early access to new equipment types, and maybe even special factors in upcoming battles (improved intel, or a special one-off auxiliary unit, or an enemy fort destroyed, etc.) Otherwise prestige is still a measure of ultimate victory. But it is not used for unit replacements....

"Support" is the second resource, and it is battle-specific, and doesn't carry over. It is an abstract measure of the overall level of logistical support available in the battle, including repair shops, flow of replacements, overall levels of fuel and ammo, etc. Support accumulates based on a per-turn value or schedule determined by the scenario designer. For instance, could be a starting value of 100, with an additional 5 per turn. And maybe bonuses for special events - eg, capture Allied supply dump at x,y for an additional 25.

Support is used up every time you take replacements, refuel or re-ammo a unit. For instance, topping up an infantry unit from 6 to 10 strength might take 4 points, doing the same for a Tiger II might take 16 points. (This would also be a built-in disincentive to load up on top-tier units - do so, and you may quickly run out of support in battle!) Potentially the scenario designer could also set a cap for how many strength points can be topped-up in a single turn, adding more to the sense of constraint.

The basic idea here is that individual battles could be made far more interesting and challenging, regardless of a player's overall prestige pool. If you're fighting in Demyansk Pocket, or at El Alamein, you should feel intensely deprived of replacements, fuel and ammo, regardless of how successful you've been in the past! More broadly, the dynamic would dampen the importance of prestige a bit, which would make campaigns simultaneously tougher for good players, and a bit more forgiving for mediocre ones.

I completely agree that the snowballing mechanism the current prestige system where:
-you can accumulate large amounts of prestige throughout the campaign and take to the next missions and
-based on your accumulated prestige buy more prestige efficient units (which avoid losses and thus increase the prestige accumulation) and where
-you might win scenario after scenario but (unknowingly) fall behind a certain prestige accumulation curve and severely punished later

must be tuned to a system, with less snowballing effect, where:
-the penalty of playing weaker than expected for the given difficulty level is much easier identified,
this will be especially important to players new to the genre. Players not having experience with the genre might think loosing 3 fighters or tanks with stars in a single scenario
just to pull of a DV instead of a MV is "acceptable" or considered "good play" must be hinted very early that this is not the case.

-players should not be able to accumulate and transfer in game currency from battle to battle in large quantities (at the very least not without penalties) and take game long investitions with that prestige (5+ strength arty) yielding even more unit buying power. Of course there should be a reward for efficient, good play, but not more in game unit buying power (leading to more efficient units)

I think the goal should be, that with a scenario win be that an efficient battle or a or pyrrhic victory (sustaining heavy losses) you should not be able to significantly affect the difficulty level for the rest of the campaign if the game evaluates player performance as an acceptable win. At max the next mission should be somewhat more difficult . That said, I dont think that sustaining very heavy losses just to occupy the victory hexes should count as a win in a campaign.

I think excelent player performance should be awarded with badges and achievements and not with more buying power granting more victories.

I dont know what the solution is, just wanted to second your opinion, that while current prestige system gives much depth to the game, it also has serious flaws. The snowballing effect must be seriously reduced IMO.

To be honest I often postpone to play the game (or even I dont play the game) bc. I have the perfectionist mentality: If a fear that I could make big mistakes and I am unsure of some unit purchasing decisions I postpone to play.

You could have a maximum points limit for a scenario. Ideally you would have a function to remove overstrength a point at a time to squeeze under the limit for deployed units. But you could also have max prestige spend in a scenario (total or per turn) to represent restricted supply or some other factor. Suddenly forcing surrender, capturing non-victory hexes bonus targets (fuel dumps for a free supply, workshops for a prestige boost or a free repair become valid options, and provided you are given just enough warning, you might field the weaker reserve units or a pile of cheap speedbumps (osttruppen, home guard), knowing that green replacements are the only option, or that some units will probably have to be lost in that scenario.

I'd like some sort of mechanism that means I don't end up with lots of the 'best' units. Whether this is rationing the best units on a per scenario basis or a secondary 'currency' such as supply I'm not really sure. However its done I'd like to the option of either having a small, elite force of the best units or a large conscript force of weaker units.

Partly this is more realistic but I also find I don't use a large number of the units available in my core force. I'd like some reason to buy, say, Hungarian units rather than German and maybe letting me have 3 minor axis units for one German is the way to do it.

i think it would be best if upgrading and acquiring new units was not handled by prestige itself, but by some resource points. Player would be then able to get more resource points by spending the prestige on it. This way, resource points could be restricted in some campaigns and scenarios, which would make campaign harder, even if you have plenty of prestige available..

This particular thing is greatly implemented in Ultimate General: Civil War game, where player can "buy" more men, better equipment, or money (which he need to get new equipment) for excess prestige, yet spending too much actually reduces the army morale, so player is required to keep the prestige high to not be penalized.. i think this could be implemented in Panzer Corps quite well, forcing player to keep his prestige up - maybe by linking prestige points to deployment slots, so bigger is your prestige more units you can control.. or something similar.

I quite like the simplicity of the current prestige system. I think the severe softcap models it very well and of course it can be made even harder with the 1.20 rules to curtail the snowballing effect. I would only make two changes to it. 1) possible incremental replacement rather than all or nothing and 2) I agree there should be more prestige for special things like surrenders, special tasks and special objectives and conditions, but these things are actually down to the particular scenario designers not the game or prestige mechanics. The multitude of excellent user made campaigns and scenarios, some of which have a very different flavour to slitherines scenarios demonstrates how good the system is. (For example 'off the top of my head' i would have to mention the incredible 'battlefield europe' by McGuba or some of nikkivdd's campaigns, there are SO many to choose from). The things mentioned like supply etc should be worked into more prominence in a campaign but this is down to the campaign designer about rewards. usually in slitherines campaigns I disband captured units for the prestige, in other user made campaigns they are integral and cannot be discarded. In slitherines campaigns the snowballing effect is just cumulative from making the correct decisions very much earlier on (e.g. farming heroes and experience). If you lose alot of core units (I hate losing core and avoid it) it just becomes a prestige driven slugfest and you miss the interesting stuff about the game.